We recently learned about the intriguing origin of the legendary Windows XP activation key . That famous set of digits (“FCKGW-RHQQ2-YXRKT-8TG6W-2B7Q8”) became a memorable aspect for many users who often found themselves memorizing it. This peculiar piece of software history serves as a unique demonstration that attempts to secure software don’t always succeed. Microsoft has had its fair share of struggles in this arena, particularly with the systems they initially employed to protect their operating systems and applications, which turned out to be remarkably ineffective.
The Rule of “Let it be Divisible by 7”
Microsoft’s first major attempt at securing Windows was with Windows 95 , which employed a system that varied based on the type of license . Unfortunately, this system turned out to be extremely inadequate. One of the most common license elements was the “CD Key,” which required users to input a code that was made up of 10 characters and segmented as follows:
- XXX : This portion could range from 000 to 998 , but with a peculiar twist: the three numbers could not be all the same (such as 111, 222, etc.).
- XXXXXXX : The second part required a simple algorithm where the number had to be divisible by seven . Users were even allowed to input zero. Although Microsoft later banned the input of all zeros, the divisibility by seven rule still remained applicable.
Thanks to these lenient rules, creating compliant combinations was relatively straightforward. Among the most frequently used CD Keys were 000-000007 and 111-1111111 .
Office 97 Used One More Digit
When it came to Office 97 , Microsoft raised the stakes by introducing an 11-digit CD Key split across two segments:
- XXXX : Ranging from 0001 to 9991 , there were no restricted numbers, though the fourth digit needed to be the third plus 1 or 2 . If this calculation exceeded 9, it would wrap around to 0 or 1 .
- XXXXXX : The second segment followed similar rules to the first one, but interestingly, it didn’t seem to have to comply with the divisibility by 7 criterion.
Examples of operational keys included 0001-0000007 and 1112-1111111 .
Things Got Complicated (A Little) with the OEM Keys
For users who received their computers with Windows 95 pre-installed, an OEM Key might have replaced the traditional CD Key. These keys were structured into four segments:
- XXXXX : This represented the date the key was printed. The first three digits could be anything from 001 to 366 , while the last two indicated the year ranging from 95 to 03 . An example key like 19296 would mean it was printed on July 10, 1996 , and to ensure compatibility with Windows XP , the last two digits should optimally be 02 .
- OEM : The second segment was strictly the immutable letters OEM .
- XXXXXXX : The third segment also adhered to the divisibility by seven rule, but with a stipulation that the first digit must always be zero .
- XXXXX : The final segment could consist of any random number of the suitable length.
Therefore, valid keys could be structured like 00100-OEM-0000007-00000 , but variations like 06900-OEM-0694207-80085 were also possible.
How Was All This Revealed?
Understanding how the Windows 95 key system operated was feasible for anyone keenly observant. However, it was the leak of the Windows NT 4.0 code that illuminated the algorithm behind these keys. This information ultimately became accessible through platforms like Archive.org , allowing individuals to showcase in-depth analyses through both video tutorials and detailed write-ups. One notable resource even detailed how to discover the “check_retail_key” function found within the setupx.dll file of Windows NT 4.0.
Nostalgia for these early days of licensing persists, reminding us that software protection is an ongoing battle that has evolved dramatically over the years. Interestingly, there are even endeavors underway to create new web browsers compatible with Windows XP , serving as a testament to the lasting impact of this operating system on users and developers alike.